1. Field of the Invention
The present invention relates to the field of wireless communication technology, and more particularly, to a method for controlling flows of a logical link layer in near field communication (NFC) software stack.
2. Description of the Prior Art
Contactless radio frequency identification (RFID) technology and interconnection and intercommunication technology are integrated and the NFC technology is produced. To improve development and popularity of the NFC technology, an NFC forum is organized by the industry. The NFC forum defines the NFC protocol system where the NFC software stack is a middleware for supporting applying development in the upper layer and for operating an NFC controller in the lower layer. A data connecting layer is arranged in the NFC software stack. The data connecting layer is basically used for transferring transparent and reliable data to a user of its layer. In addition, the data connecting layer is used for framing, error correction, conservation, and flow control.
A traditional NFC Forum Logical Link Protocol does not regulate the size of a Receive Window; instead, the size of the Receive Window is recommended to be zero to 15 in the Protocol. The NFC Protocol has a physical layer, which is a wireless communication protocol, and the physical layer tends to make troubles. The smaller the Receive Window is, the larger the bandwidth needs. The Logical Link Protocol is a Peer to Peer (P2P) business service. This kind of business service has a larger amount of data and a larger corresponding data frame. Thus, a larger buffer zone is required when the size of the Receive Window is much larger. However, the NFC software stack works in an embedded environment, so memory resource of the NFC software stack is relatively limited. Once the buffer zone becomes larger, the performance of the system will be affected.
In addition, a plurality of NFC controller chips support the P2P application only in the passive mode. The mode is a half-duplex working mode, which means that the actions “send” and “receive” take turns. If the size of the Send Window and the size of the Receive Window are too large, one of the communicators is in state of sending and resending all the time, and the other is deprived of sending time, resulting in the struggle between unbalance of bandwidth utilization and consumption of memory resource.
Therefore, the conventional technology has room to be improved.